i just made one that is similar to the one you are making. it i s 68" ntn and drew 42# at 28" it is 1" at the handle and fades out to 1.5". it is 1.5" out to the mid limb, and then it fades down to 5/8 of an inch at the nock. it is very smooth with very little stack. not to mention it slings an arrow very well! tis was not my first try , but it is the first one to stay together. make sure to take a look at jawge's web site. my first couple broke because they had run outs, which he explains all about. good luck.
eric